کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2070503 1544499 2007 23 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Quantification of risk from fetal exposure to diagnostic ultrasound
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیوفیزیک
پیش نمایش صفحه اول مقاله
Quantification of risk from fetal exposure to diagnostic ultrasound
چکیده انگلیسی

Biomedical ultrasound may induce adverse effects in patients by either thermal or non-thermal means. Temperatures above normal can adversely affect biological systems, but effects also may be produced without significant heating. Thermally induced teratogenesis has been demonstrated in many animal species as well as in a few controlled studies in humans. Various maximum ‘safe’ temperature elevations have been proposed, although the suggested values range from 0.0 to 2.5° C. Factors relevant to thermal effects are considered, including the nature of the acoustic field in situ, the state of perfusion of the embryo/fetus, and the variation of sensitivity to thermal insult with gestational stage of development. Non-thermal mechanisms of action considered include acoustic cavitation, radiation force, and acoustic streaming. While cavitation can be quite destructive, it is extremely unlikely in the absence of stabilized gas bodies, and although the remaining mechanisms may occur in utero, they have not been shown to induce adverse effects. For example, pulsed, diagnostic ultrasound can increase fetal activity during exposure, apparently due to stimulation of auditory perception by radiation forces on the fetal head or auditory structures. In contrast, pulsed ultrasound also produces vascular damage near developing bone in the late-gestation mouse, but by a unknown mechanism and at levels above current US FDA output limits. It is concluded that: (1) thermal rather than nonthermal mechanisms are more likely to induce adverse effects in utero, and (2) while the probability of an adverse thermal event is usually small, under some conditions it can be disturbingly high.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Biophysics and Molecular Biology - Volume 93, Issues 1–3, January–April 2007, Pages 331–353
نویسندگان
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